Two- or three-component catalysts composed of (i) sulfur or sulfur compound (H2S, CS2, COS, Na2S), (ii) basic additive (triethylamine, CH3ONa, Na2S), and usually (iii) vanadium(V) compounds (e.g. NH4VO3) were found to catalyze efficiently the reaction of CO + H2O with isomeric nitrophenols to give the corresponding aminophenols. The reaction proceeds smoothly at 398 and 483 K and initial pressure of 7 MPa, and its rate increases from 2- to 4-nitrophenol. The selectivity to aminophenols exceeding 96 per cent was obtained at the water to nitrophenol molar ratio higher than 5. The solvents such as methanol and dioxane ensured better contact of the reactants, which was necessary for achievement of such a high selectivity. The effectiveness of the sulfur components (based on the S content) is expressed by the following sequence: S : CS2 : Na2S : H2 S : COS = 1 : 1.2 : 2.5 : 10 : 11. The reaction takes place also under the reduced CO pressure to 0.1 - 0.35 MPa. Formation of side products and mechanism of the reaction are discussed.
由(i)硫或硫化合物(H2S,CS2,COS,Na2S),(ii)碱性添加剂(三乙胺,CH3ONa,Na2S),以及通常(iii)钒(V)化合物(例如NH4VO3)组成的两种或三种组分的催化剂被发现能够有效催化CO + H2O与同分异构硝基苯酚的反应,产生相应的氨基苯酚。该反应在398和483K的初始压力为7MPa的条件下顺利进行,其速率从2-硝基苯酚增加到4-硝基苯酚。当水对硝基苯酚的摩尔比高于5时,氨基苯酚的选择性超过96%。溶剂如甲醇和二氧六环确保了反应物的更好接触,这对于实现如此高的选择性是必要的。硫组分的有效性(基于S含量)由以下顺序表示:S:CS2:Na2S:H2S:COS = 1:1.2:2.5:10:11。该反应也在CO压力降至0.1-0.35MPa时发生。讨论了副产物的形成和反应机理。